Review: Hawker Siddeley Trident


By far one of the most advanced and iconic British aircraft of the 1960’s, the Trident was Britain’s attempt at a short-to-medium range jet airliner that was called upon by state-owned carrier British European Airways for their premier routes in Western Europe. However, it’s involvement with BEA would later become a thorn in its side, and would ultimately destroy the Trident’s chances, especially after the introduction of the Boeing 727 from North America.

With the introduction of Jet Airliners in 1952, pioneered by the De Havilland Comet, many airline managers and economists remained sceptical and advocated turboprop airliners as replacements of piston-engined airliners. Initial resentment to the jet airliner proposals however were quickly warmed, with BEA, who had openly rejected the idea of jet powered aircraft, going on to say they would consider jets to work alongside their Turboprop fleet. These jets would be required to carry a payload of some 20,000lb (the equivalent of 70 passengers) up to 1,000 miles, and have the ability to use runways of up to 6,000ft. Other requirements included a cruising speed of 610 to 620mph using two or more engines.

Tridents undergo construction in the Hatfield factory.

Initially, four British aircraft manufacturers took up the challenge of designing such a stringent aircraft. AVRO proposed the AVRO 740 Trijet, but would later join forces with Bristol and Hawker Siddeley. Vickers proposed a short-range version of their VC-10 dubbed the VC-11. The de Havilland company considered three possible contenders for the specification. Two were four-engined developments of the Comet: the D.H.119 and the D.H.120, the latter also intended for offer to British Overseas Airways Corporation (BOAC). The third, the D.H.121 announced in May 1957, had three engines and was pitched at BEA. In February 1958, BEA announced that the D.H.121 had come closest to its requirements and that it would order 24 with options on 12 more. However, development of the D.H. 121 was stalled for another 6 months by the British Government, in which time they had taken favour to Hawker Siddeley for Industrial policy reasons. Meanwhile, BEA has taken a shine to the Sud Aviation Caravelle of France, but was deemed politically unacceptable, and thus the De Havilland option was taken up.

Over time the design was tinkered and altered due to BEA’s continually changing requirements for the aircraft. Eventually, the aircraft, now dubbed the ‘Trident’, was brought to a final design. The aircraft would be constructed of metal, and wings would be swept back at 35 degrees. Power came from three Rolls Royce Spey engines mounted at the rear, with the T-Tail design bearing a similarity to the later Boeing 727. Performance wise, the Trident was capable of 610mph cruising speeds, and could take off in less than 6,000ft of runway. The main competition however, the newly developed Boeing 727 of the United States, could take off in 4,500ft. In flight, the Trident could descend routinely at rates of 4,500ft/min, with room to cater for emergency descents.

However, the Trident’s main party piece was in fact it’s automatic landing system, the first of its kind in the world. The Automatic Blind Landing system was developed by Hawker Siddeley and Smiths Aircraft Instruments, and was able to guide the aircraft automatically during airfield approach, flare, touchdown and even roll-out from the landing runway. The system was intended to offer autoland by 1970. In the event, it enabled the Trident to perform the first automatic landing by a civil airliner in scheduled passenger service on 10th June 1965, and the first genuinely “blind” landing in scheduled passenger service on 4th November, 1966.

This system was primarily developed to overcome the problems of heavy fog at London’s Heathrow Airport, which could often result in long delays or diversions to other airports. These advanced avionics though needed room inside the aircraft, and thus were placed underneath the cockpit, resulting in the nose landing gear being offset from the centre of the aircraft, leading to the nose wheel retracting sideways.

Hawker Siddeley Aviation which absorbed de Havilland, needed additional customers for the Trident, so entered into discussions with American Airlines in 1960. They demanded an aircraft with a longer range, which meant that the original DH121 design would have fulfilled American’s requirements almost perfectly. To fill American’s needs, design began on a new Trident 1A, powered with uprated Rolls-Royce Spey 510’s greater thrust and a larger wing with more fuel. American Airlines eventually declined the aircraft in favour of the Boeing 727, an aircraft which filled the original DH121 specifications almost exactly.

A striking publicity photo showing the Trident departing its home factory at Hatfield.

The first Trident 1, G-ARPA, made its maiden flight on 9th January, 1962 from Hatfield Aerodrome, and entered service on 1st April 1964. By 1965, there were 15 Tridents in BEA’s fleet and by March 1966, the fleet had increased to 21.

Sales for the Trident 1 were sadly low, with only three being sold to Kuwait Airways and Iraqi Airways, four for Pakistan International Airlines (later sold to CAAC), two each for Channel Airways and Northeast Airlines of Britain, and one for Air Ceylon. Channel Airways aircraft were operated with cramped, 21in pitch, seven-abreast seating in the forward section (and people say Ryanair is cramped!).

Later, a new Trident, the Trident 2E, was launched, which included modified engines for greater journey length and a longer fuselage for more capacity. Again, sales were sadly lukewarm at best, with BEA buying 15, two for Cyprus Airways and 33 by CAAC, the Chinese national airline. The first flight of this version was made on 27th July, 1967 and it entered service with BEA in April 1968.

A Trident 3B on short final while wearing BEA colours.

The final variant of the Trident, the 3B, was the largest of the fleet, with a capacity of 180 seats. The design came from an earlier proposal of two different aircraft to combat the likes of the newer Boeing 737, both being by Hawker Siddeley. The HS132 intended to have two engines like a DC-9 and would take 158 passengers, whilst the HS134 would take 180 passengers and have engines under the wings, making the aircraft look similar to that of the modern day Boeing 757. Both plans however were declined by BEA, who intended instead to take on Boeing 727’s and 737’s to replace their fleet of 1-11’s and Tridents, but the Government turned them down. In the end a stretched Trident was born and dubbed the 3B. In all, 26 aircraft were ordered by BEA, being launched in December 1969. A later version with extended range fuel tanks was also built called the Super Trident 3B. In all, only 35 of these planes were built, the remainder being sold to CAAC.

A CAAC example performs the legendary Runway 13 ‘Checkerboard’ approach at Kai Tak Airport in Hong Kong.

In the end, only 117 Tridents were ever built, in comparison to the 1,832 Boeing 727’s built in the same time period. After the end of production, the Tridents ambled along in a life on borrowed time, their design being quickly overtaken by their Boeing competitors. BEA was eventually merged with BOAC to form British Airways in 1974, who largely consumed the other British Trident operators throughout the 70’s and 80’s before retiring the fleet in 1985. The last known flights of the Hawker Siddeley Trident were by CAAC in the early 1990’s.

During its commercial lifetime, 9 Tridents were involved in accidents of which 5 were fatal, resulting in 348 fatalities both on the aircraft or on the ground. However, none of these crashes were due to a fault with the Trident itself, instead being due to pilot error, weather related or other external forces.

The first major crash involving the Trident was on 18th June, 1972, where pilot error caused British European Airways aircraft G-ARPI to stall on departure from Heathrow, killing 118. The crash happened following the merger and nationalisation of British national carrier BOAC and the more mundane BEA, together with a pilot’s strike. The result was bad sentiment between what was considered the more prestigious BOAC and the humdrum BEA crews, of which one of each was flying the Trident during the fatal flight. It was found that due to bickering and disagreement in the cockpit, they failed to notice the aircraft was in the process of stalling and by the time they realised their error the aircraft was beyond saving. It today remains the worst accident on British soil, though if terrorist acts are considered the title goes to Pan Am 103.

Tridents dominate the terminals at Heathrow, this shot being taken during the transition period between BEA and British Airways.

The next major incident happened on the 10th September, 1976, when over Zagreb, British Airways Flight 476, a Trident, and Inex-Adria Flight 550, a Douglas DC-9, suffered a mid-air collision resulting in 176 deaths on both aircraft, 63 on the Trident. The collision was the result of a procedural error on the part of Zagreb air traffic controllers, who failed to notice the two aircraft approaching each other at the same altitude and made mistakes in their attempts to give evasive instructions.

Some of the more spectacular and tragic crashes however happened in China, where the Trident was popular with Chinese government owned carrier CAAC (Civil Aviation Administration of China). On the 14th March, 1979, an unqualified pilot stole a Trident from Beijing airport and proceeded to fly around before accidentally crashing into a factory, killing 32 on the ground and 12 crew aboard the aircraft, which had been preparing to operate another flight.

On April 26th, 1982, CAAC Flight 3303 was flown into a hillside near Yangshuo during bad weather, killing all 112 aboard.

The last major Trident accident was also due to weather, this being CAAC Flight 301 on the 31st August, 1988, which was attempting to land at the famous Kai Tak Airport in Hong Kong. The aircraft approached Runway 31 (the easier harbour approach) too low and struck approach lights before hitting the end of the artificial land on which the runway was built, ripping off the starboard side main gear and causing the aircraft to slip into the harbour, killing 7 passengers.

Multiple Tridents were also written off through no fault of their own, some of which were due to quite spectacular incidents.

After retirement, this British Airways Trident was dolled up in the brand new ‘Landor’ livery, but never actually flew with it. It was used for training purposes prior to preservation.

On the 3rd July, 1968, an Airspeed Ambassador operated by BKS Air Transport crashed on landing at London Heathrow due to metal fatigue related mechanical failure. As the aircraft was landing on Heathrow’s runway 27R the left wing dropped, and the wing tip and left landing gear touched the grass adjacent to the runway. The crew tried to increase power to go-around and climb away, but the bank angle increased. The aircraft hit two parked empty BEA Tridents, knocking the tail fin off one (G-ARPI) and slicing off the entire tail section of the other (G-ARPT), as well as damaging a nearby Vickers Viscount. The Ambassador cartwheeled following the impact and slid upside down coming up against the ground floor of what is now Terminal 2 before exploding. This huge crash, quite possibly the worst in Heathrow’s history, resulted in 6 deaths, but it was a miracle that the two Trident’s weren’t carrying passengers and that the area in Terminal 2 where the Ambassador exploded wasn’t busy, otherwise there could have been an untold number of fatalities. The Ambassador itself was carrying eight Horses and five Grooms as part of a delivery for businessman William Hill. Three of the five grooms were killed as were the flight crew, and all eight horses died in the crash as well. G-ARPT was written-off and subsequently broken up, while G-ARPI was repaired and returned to service, but was later destroyed in the 1972 Staines accident.

Trident 5B-DAB still languishes under the hot Cypriot sun, 40 years after it was abandoned.

Another written-off but still extant example is Trident 2E 5B-DAB, which has sat perfectly still at the abandoned Nicosia International Airport in Cyprus since the Turkish invasion of 1974. In response to the overthrow of democratically elected president of Cyprus, Archbishop Makarios, and the subsequent ferrying of Greek troops to Cyprus to support their coup, Turkey invaded the island on the 20th July, 1974, with the airport being their immediate strategic target. The airport was bombed heavily and aircraft on the ground were either blown up in the assault or strafed with small-arms fire. Three of Cyprus Airways’ Tridents were on the ground at the time, one, 5B-DAE, was destroyed in the attack, while 5B-DAB and 5B-DAC were heavily damaged. A ceasefire was eventually declared by the UN on the 18th August that year, and the airport is now situated in the UN enforced Buffer Zone that splits the island in two, into which very few are allowed. In 1977, a British Airways engineering crew were allowed access to the Tridents to assess their damage and possible repair for further use. 5B-DAC had only suffered a few bullet holes that were easily patched before being flown back to Heathrow, where it was later repaired, returned to service, flew for another 4 years, before being retired to Duxford Air Museum in 1982. 5B-DAB on the other hand has a much more depressing fate, the aircraft having never been officially decommissioned by the now defunct Cyprus Airways, and has been sat in the same position on the apron for 42 years though heavily stripped, essentially making it a time capsule along with everything else at the airport.

G-AWZK, now preserved lovingly at the Manchester Aviation Viewing Park.

Today, no Trident’s are airworthy, and apart from 5B-DAB in Cyprus and 3 aircraft being used as Fire Training aircraft around the UK, 5 Tridents have been officially preserved, 4 in Britain and 1 in China. In China as well there are 3 incomplete airframes at the Beijing Airplane Museum, and in 2008, the former personal Trident of Chairman Mao was found to be put up for sale to merchants, though what has become of this aircraft is unknown.

As for the Trident itself though, it’s yet another sad example of a great British concept that never made it to legend. Whilst many Boeing 727’s of the same period continue to ply their trade in the skies, the small and subtle reign of the Trident has long since been silenced. But I will say, in spite of the delayed introduction, the poor sales and constantly changing requirements, being undercut by Boeing and Douglas, the Trident still managed to make an impact technologically, with it’s Automatic Landing system now something modern airliners take for granted.

If only the plane that system had been associated with had succeeded in the same way.

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